E. coli causes up to 95% of urinary tract infections. Image: © Dennis Kunkel Microscopy, Inc./Visuals Unlimited/Corbis
Increasing antibiotic resistance stemming from the use of antibiotics in raising livestock is contributing to growing difficulty in treating urinary tract infections, according to new research published in the Journal of Medical Microbiology. Dr. Pak-Leung Ho and colleagues at the University of Hong Kong say that genes which encode antibiotic resistance are increasingly prevalent in both humans and animals — and that they reflect growing antibiotic resistance caused by the spread of bacteria through contaminated water, direct contact with animals and the global food supply.
Researchers analyzed Escherichia coli (E. coli) bacteria — the cause of the vast majority of urinary tract infections — in fecal samples taken from both humans and animals. They found the gene aacC2, which encodes resistance to the common antibiotic gentamicin, in 80% of samples.
The ability for antibiotic resistance to potentially transfer from animals to humans through the food chain suggests that, with an increasingly global food supply, isolating resistance to a specific region could be nearly impossible, the study authors say. And, they point out, that’s particularly bad news as antibiotic resistance derived from the food supply can minimize the efficacy of antibiotics commonly used to treat infections in humans.
While the research was conducted in Hong Kong, professor Chris Thomas, of the School of Biosciences at the U.K.’s University of Birmingham, told the BBC that antibiotic-resistant strains of E. coli have been found in the U.K. as well:
“Antibiotic use in animal husbandry is tightly controlled in Europe. But even if the problem is being curbed here, people traveling abroad and moving from community to community will bring resistance with them and it will spread… It’s a worldwide problem.”
Resistance to certain antibiotics can be overcome by using stronger antibiotics, but in time bacteria may develop resistance to these medications as well, experts say. According to the figures from the National Institutes of Health, urinary tract infections are the second most common form of infection in the body, affecting more women than men and prompting more than 8.3 million people to seek medical attention each year.